This invention concerns an improvement to the fastener positioning device disclosed by the inventor's prior patent, U.S. Pat. Re. No. 29,855, reissued on Dec. 5, 1978. The types of fasteners generally used with the positioning device disclosed in U.S. Pat. Re. No. 29,855 and which may be used with the present invention have enlarged heads with shanks which extend therefrom. An exemplary use of such fasteners may be for securing roofing materials to a roof or the like. The disclosure of U.S. Pat. Re. No. 29,855 is herein expressly incorporated by reference.
In the device of U.S. Pat. Re. No. 29,855, fasteners are moved along a track from a feed bowl into a notch formed at the end of an elongated member. The side walls of the notch are open relative one end and one side of the elongated member so as to permit the passage of fastener shanks therethrough. Fasteners are placed into the notch through its side opening and are retained therein by a leaf spring. The entire elongated member including the notch associated therewith is slidably mounted on a housing. Reciprocation of the elongated member brings the notch with fastener retained therein into proximity with a hammering device having a magnetized hammering head. The fastener is then caused to exit through the end opening of the notch and become magnetically engaged with the hammering head. Operation of the hammering device then seats the fastener into a desired medium.
In such prior device, it is necessary for the fasteners to be fed through a track directly into a specific alignment with the notch and its leaf spring so that subsequent reciprocation of the elongated member will move each fastener into proper relationship with the magnetized head of a hammering device. If the fastener is not initially seated into such notch with the necessary alignment, it is unlikely that the device will accomplish its desired goal of properly advancing fasteners to a speific point in a given orientation suitable for automatic hammering.
Other prior art devices have shared the goal of properly feeding nails, fasteners or the like to a hammering position. Examples of such other prior art devices are disclosed by the following U.S. patents:
______________________________________ U.S. Pat. No. INVENTOR(S) ISSUE DATE ______________________________________ 3,765,588 Frederickson October, 1973 4,030,655 Rothfuss et al. June, 1977 3,747,828 Dupee et al. July, 1973 4,227,637 Haytayan October, 1980 ______________________________________
Frederickson utilizes a magnetic nail shaft aligning groove for attracting and retaining nails fed in seriatim to such groove by a delivery means. The nails are first magnetically engaged when received by the nail shaft aligning groove, and are not otherwise magnetically engaged along the length of a member as they are moved into a given hammering position. The remaining cited references utilize various techniques and apparatuses for positioning fasteners, but none which teach the present invetion. For example, Dupee discloses a system which utilizes fastener feed ducts both gravity and vacuum-actuated to feed fasteners to a desired position.